diff --git a/README.md b/README.md
index fb051f8..c72dfef 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,7 @@ Opens a dashboard at `http://localhost:50234` showing live agent sessions, tool
 | Flag | Description |
 |------|-------------|
 | `--port <number>` | Server port (default: 50234) |
+| `--host <address>` | Bind address (default: localhost, use 0.0.0.0 for all interfaces) |
 | `--no-browser` | Don't auto-open browser |
 | `--project <path>` | Set project directory for plan tracking |
 | `--help` | Show help |
diff --git a/src/server/cli.ts b/src/server/cli.ts
index 47df7ef..7d7f6dd 100644
--- a/src/server/cli.ts
+++ b/src/server/cli.ts
@@ -2,6 +2,7 @@ import { DEFAULT_PORT } from "../shared/constants";
 
 export interface CLIFlags {
   port: number;
+  host: string;
   noBrowser: boolean;
   projectPath: string | null;
   showHelp: boolean;
@@ -11,6 +12,7 @@ export function parseArgs(): CLIFlags {
   const args = process.argv.slice(2);
   const flags: CLIFlags = {
     port: DEFAULT_PORT,
+    host: "localhost",
     noBrowser: false,
     projectPath: null,
     showHelp: false,
@@ -29,6 +31,17 @@ export function parseArgs(): CLIFlags {
         flags.port = parseInt(portValue);
         i++;
       }
+    } else if (arg === "--host") {
+      const hostValue = args[i + 1];
+      if (hostValue && /^[a-zA-Z0-9.\-:]+$/.test(hostValue)) {
+        flags.host = hostValue;
+        i++;
+      } else if (hostValue) {
+        console.warn(`[ocwatch] Invalid --host value ignored: ${hostValue}`);
+        i++;
+      } else {
+        console.warn(`[ocwatch] --host requires a value`);
+      }
     } else if (arg === "--project") {
       const projectPath = args[i + 1];
       if (projectPath) {
@@ -49,6 +62,7 @@ Usage: ocwatch [options]
 
 Options:
   --port <number>      Server port (default: 50234)
+  --host <address>     Bind address (default: localhost, use 0.0.0.0 for all interfaces)
   --no-browser         Skip auto-opening browser
   --project <path>     Set default project filter
   --help, -h           Show this help message
@@ -56,6 +70,7 @@ Options:
 Examples:
   ocwatch
   ocwatch --port 50999
+  ocwatch --host 0.0.0.0
   ocwatch --no-browser
   ocwatch --project /path/to/project
 `);
diff --git a/src/server/index.ts b/src/server/index.ts
index 9e786c6..a9da550 100755
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -69,6 +69,8 @@ async function getDefaultProjectIdFromFlag(projectPath: string | null): Promise<
 
 const defaultProjectIdPromise = getDefaultProjectIdFromFlag(flags.projectPath);
 
+const isWildcard = flags.host === "0.0.0.0" || flags.host === "::";
+
 const app = new Hono();
 
 app.use("*", compress());
@@ -76,10 +78,18 @@ app.use("*", errorHandler);
 
 app.use(
   "/api/*",
-  cors({
-    origin: ["http://localhost:3000", "http://localhost:50234"],
-    credentials: true,
-  })
+  cors(
+    isWildcard
+      ? { origin: "*", credentials: false }
+      : {
+          origin: [
+            `http://localhost:3000`,
+            `http://localhost:${flags.port}`,
+            `http://${flags.host}:${flags.port}`,
+          ],
+          credentials: true,
+        }
+  )
 );
 
 registerRoutes(app, { defaultProjectIdPromise });
@@ -103,10 +113,13 @@ app.notFound(async (c) => {
 export { app };
 
 const port = flags.port;
-const url = `http://localhost:${port}`;
+const hostname = flags.host;
+const displayHost = isWildcard ? "localhost" : hostname;
+const url = `http://${displayHost}:${port}`;
 
 export default {
   port,
+  hostname,
   fetch: app.fetch,
 };